沙尘粒子的物理化学与光学特性

利用激光雷达、卫星、太阳光度计、地面能见度,结合分析化学等资料研究了长程运输到台湾地区的各种粒子的物理化学与光学特性。激光雷达与太阳光度计可以得到沙尘与云的高度分布、大气光学厚度、消光以及粒子大小分布等的信息。地面测站的化学分析等显示沙尘具有增强的水溶性离子:如Na+、K+、Mg2+、Ca2+及Cl-、NO3-、SO42-等。由于这些物质的亲水性,使它们成为云的凝结核。根据粒径分布随着湿度增加而变大,及在一些沙尘事件中观察到云的例案可以知道它们对气候的影响。

Physicochemical and Optical Properties of Dust Particles

The physicochemical and optical properties of various aerosols following long range transport to Taiwan were studied by using various data of instruments including lidar,satellite,sun-photometer and chemical analysis. The lidar and sun-photometer provided the height profiles,optical thickness, extinction and particle size distributions. The ground chemical analysis showed that the dust particles were coated with soluble ions such as Na+,K+,Mg2+,Ca2+,Cl-,NO3-,SO42- and so on. Because of these coatings, the particles could become hydrophilic therefore forming potential cloud condensation nuclei. Lidar measurements showed that the particle sizes increased with humidity,therefore,affecting the climate through cloud effects.